This invention relates generally to fasteners for fastening objects to metal channel framing and, more particularly, to a nut having means thereon for clamping the nut to the channel prior to and during securement of the object to the channel.
Electrical conduit, pipes, fixtures, etc. are commonly supported overhead or vertically by channel framing conventionally having side flanges with inwardly turned, hook-shaped lips defining a slot therebetween. Typically, an elongate nut (narrower but longer than the width of the slot) is used for securing objects to the framing, the nut first being aligned with, entered into and passed through the slot, and then turned 90.degree. to a crosswise position with the outside face of the nut engaging the inside faces of the channel lips. Various means have heretofore been used for holding the nut against the channel in its crosswise position prior to and during securement of an object to the channel.
One such means is a coil compression spring on the inside face of the nut. Upon insertion of the nut into the channel, this spring reacts from the channel bottom and pushes the nut against the channel lips. This arrangement has several serious disadvantages, however, one being that each channel of different depth requires a spring of correspondingly different lenth, thus greatly increasing the number of fastener sizes which have to be stocked. Moreover, while securing parts to the framing, the nuts tend to tilt and topple over into the channel. It is also difficult to use the channel as a raceway for conduit, wires or the like since the spring substantially blocks the entire channel.
Other prior art devices utilize a coil spring attached to the outside face of the nut for spanning the channel and pulling the nut into engagement with the channel lips. This type of device also has its drawbacks, however, inasmuch as the spring tends to slip off the lips of the channel and the nut to fall into the channel.
The fastener disclosed in my U.S. Pat. No. 4,146,074, issued Mar. 27, 1979, solves the aforementioned problems in that it provides a clear channel for carrying conductors and remains securely in place on the channel prior to and during securement of an object to the channel. However, while the installation and use of this fastener have been entirely satisfactory, its manufacture has required that the sides of the nut be slotted. This, of course, requires a separate machining step with its attendant costs. Moreover, it makes the fastener more difficult to assemble, thereby increasing labor costs.
Reference may be made to U.S. Pat. Nos. 1,306,100 and 3,483,910, and British Pat. Nos. 513,368 and 1,061,149, all of which disclose fasteners of the same general type as that of the fastener of this invention.